Fibre channel (FC) protocol is a transmission protocol with high performance applied in a storage area network (SAN). For a FC network, the whole network can be divided into multiple virtual storage area networks (VSAN) using a virtual fabric technique, wherein different VSANs are logically separated and not able to provide data access to each other. Since different VSANs are isolated from one another, FC-ID addresses of devices in different VSANs can overlap.
Fibre Channel over Ethernet (FCoE) is a technology for bearing FC protocol over Ethernet. A switch for supporting FCoE protocol is called a FCoE Forwarder (FCF), and a communication entity device supporting FCoE protocol is called an Ethernet node (ENode). For example, the ENode can be a server or a disk array, etc.
Referring to FIG. 1, FIG. 1 is a schematic diagram illustrating a conventional FCoE network. In FIG. 1, the whole network is divided into 2 VSANs, i.e. VSAN 1 and VSAN 2. An ENode within a VSAN can only access other ENodes of the same VSAN. Each of FCF switch1 101 and FCF switch2 102 has two F ports. Access VSAN IDs of the two ports of each switch are configured as VSAN1 and VSAN2. Furthermore, an E port is configured as a Trunk of VSAN1 and VSAN2.
When an FCF switch receives an FC message transmitted from an ENode (which can be any of Server1 103, Server2 104, Disk array1 105 and Disk array2 106), it needs to encapsulate the FC message into an Ethernet message. FC messages from different VSANs may be transmitted in the same Ethernet link. On the FC protocol layer, different VSAN IDs are used for identifying FC messages from different VSANs. On the Ethernet protocol layer, in order to avoid message address conflict and to guarantee safety, there is a need to distinguish FC messages from different VSANs.
In order to obtain the above mentioned object, in the existing FCoE protocol, different VSANs in the FC protocol are mapped into different VLANs in an Ethernet, thereby forming one-to-one correspondence between the VSANs and the VLANs (that is, VSAN IDs and VLAN IDs have one-to-one correspondence). Therefore, FC messages from different VSANs can be isolated in an Ethernet due to isolation of Ethernet messages among different VLANs. However, there is one-to-one correspondence between VSANs and VLANs, and so each VSAN requires a dedicated VLAN which may be a waste of VLAN resources.